Often when first examining a patient, clinicians can find it difficult to differentiate between bacterial versus viral caused infections. About 30 million cases of tonsillopharyngitis are diagnosed every year, with viruses being the predominant cause of infection. Rhinovirus, adenovirus, coxsackievirus, echovirus, coronavirus, and Epstein-Barr viruses are the most common causes of viral tonsillopharyngitis. Misdiagnosis, however, often results in over-prescription of antibiotics, which is a growing public health concern due to the creation of antibiotic-resistant microbes. In fact, clinicians fail to distinguish between viral and bacterial infections of the throat approximately 50% of the time. Of the estimated 6.7 million pharyngeal-related adult visits to primary care providers each year, antibiotics are prescribed 70-75% of the time.
Throat cultures remain the “gold standard” for diagnosis, but results may not be available for up to 48 hours. Although relatively quick, use of rapid strep screening tests can be problematic due to an error rate of between 5-40%. In addition, the available rapid tests are only meant to diagnose group A beta hemolytic streptococci, even though other bacteria may be involved (such as Neisseria gonorrhoeae, Corynebacterium diphtheriae, Haemophilus influenzae. Moraxella catarrhalis, and group C and group G streptococcus). Group C Streptococcus, in particular, can be more common in college students and young adults and is not detected by the rapid strep tests. Typically, a negative test result is taken to mean the infection is most likely viral, but a culture is still taken and results may contradict the original rapid test result. The patient may have been prescribed antibiotics as a precaution while waiting for the culture results, or they may be called several days later and informed that they need to take antibiotics if the culture results come back positive. During that time, they may have unknowingly exposed others to the infection as well. Thus, a need exists for a test which would allow clinicians to rapidly and accurately distinguish between bacterial and viral throat infections.
Beyond the clinician's office, there is an even larger need for devices that provide additional information to the consumer. Absenteeism due to illness continues to burden businesses financially, accounting for 15% of payroll expenses, on average. When workers become ill, time is taken from their jobs not only to rest and recover, but often times to go to the doctor for a diagnosis and treatment. Moreover, workers may have to take time out of their schedule to bring their sick children to the doctor.
Because common viral infections which might cause a sore throat are not usually serious or helped by antibiotics, consumers might act differently if they had more information about their illness before going to the physician. Knowing in advance that their symptoms are more likely to be viral in nature might allow a consumer to save money and time on doctor visits and treat themselves properly with rest, fluids, and over-the-counter medicines. Similarly, being informed that an infection is most likely bacterial in nature could guide consumer behavior as well. An individual could be more informed about when they need to see a physician and also might have more reasonable expectations about the kinds of treatments which could help their condition (over-the-counter meds vs. prescription antibiotics, for example). Therefore, consumers could benefit greatly from devices which provide additional information about their symptoms and treatment options.
Hence, a need exists for an optical indicator that can differentiate between bacterial and viral pathogens. Further, an indicator device that can be easily used by in clinical or at-home settings. can help provide quick, accurate and consistent diagnostic or detection information for both healthcare providers and general consumers.